The inventive concepts relate to integrated circuit devices, and more particularly, to integrated circuit devices including a field effect transistor.
With the development of electronic technologies, integrated circuit devices have been rapidly downscaled. Semiconductor devices can benefit from both a high operating speed and an operational accuracy, and thus, research into optimizing the structure of transistors included in the semiconductor devices has been conducted.
As the size of transistors, decreases, a reduced gate length of the transistors can cause threshold voltage variations among a plurality of transistors performing the same function.